1. Field of the Invention
The invention relates to an item of seating furniture, particularly an office chair, comprising at least one seat adjusting device, for example for adjusting the seat height, with, engaging the two parts of the seat which have to be adjusted in respect of each other, a spring element, particularly a pressurized fluid spring, and comprising a locking device for the separable possibly resiliently yielding fixing of the two seat parts in whichever adjusted position is chosen.
2. Description of the Prior Art
In the case of known types of seating furniture of this type, the desired adjusted position of the seat is achieved in that, starting from an initial adjustment of the seat with the spring element in its maximum relaxed state (seat raised to its highest setting; back rest pivoted forwards), the person sitting on the seat releases the locking device of the corresponding seat adjusting device, for example the seat height adjusting device, whereupon the seat padding is lowered under the body weight until finally, when the desired height is reached, the person in question releases the lever of the locking device so that it returns to its locked position and the seat is fixed at the desired height. The seat back is adjusted in a corresponding manner. Where many office chairs are concerned, still further adjustment possibilities are available such as, for example, the angle of inclination of the seat and adjustment of the height of the back rest cushion, for which purpose a corresponding plurality of actuating elements such as, for example, levers are provided on the chair. For technically unskilled persons, difficulties frequently occur in achieving an optimum adjustment of the seat parameters.
In motor vehicles, seat adjustment-devices are known which make it possible to approach the desired seat position with the aid of electrical adjusting drives. Such electrical adjusting drives are inappropriate in the case of seating furniture such as, for example, office chairs on grounds of cost. Also, such positioning motors require relatively considerable energy so that items of seating furniture would have to be connected to external voltage sources such as, for example, to the main network, which would result in restricted freedom of movement.